code: def testWalkPostOrder(self):
      dir_path = os.path.join(self._base_dir, "test_dir")
      self._setupWalkDirectories(dir_path)
      # Now test the walk (topdown = False)
      all_dirs = []
      all_subdirs = []
      all_files = []
      for w_dir, w_subdirs, w_files in gfile.walk(
          dir_path, topdown=False
      ):
          all_dirs.append(w_dir)
          all_subdirs.append(w_subdirs)
          all_files.append(w_files)
      self.assertCountEqual(
          all_dirs,
          [
              os.path.join(dir_path, item)
              for item in [
                  "subdir1_1",
                  "subdir1_2/subdir2",
                  "subdir1_2",
                  "subdir1_3",
              ]
          ]
          + [dir_path],
      )
      self.assertEqual(dir_path, all_dirs[4])
      self.assertLess(
          all_dirs.index(os.path.join(dir_path, "subdir1_2/subdir2")),
          all_dirs.index(os.path.join(dir_path, "subdir1_2")),
      )
      self.assertCountEqual(all_subdirs[0:4], [[], [], ["subdir2"], []])
      self.assertCountEqual(
          all_subdirs[4], ["subdir1_1", "subdir1_2", "subdir1_3"]
      )
      self.assertCountEqual(
          all_files, [["file2.txt"], [], [], [], ["file1.txt"]]
      )
      self.assertLess(
          all_files.index(["file2.txt"]), all_files.index(["file1.txt"])
      )
  
imports: import os.path
  from tensorboard import test
  from tensorboard.compat.tensorflow_stub import compat, errors
  from tensorboard.compat.tensorflow_stub.io import gfile
label_desc: Use image node_id 16 for calling the FileIoTest obj's underlying member method code with example usage: obj.testWalkPostOrder() without return types